fix invW

Author: ChrisRackauckas

src/ModelingToolkit.jl

@@ -18,6 +18,7 @@ include("variables.jl")
 Base.promote_rule(::Type{T},::Type{T2}) where {T<:Number,T2<:Expression} = Expression
 Base.one(::Type{T}) where T<:Expression = Constant(1)
 Base.zero(::Type{T}) where T<:Expression = Constant(0)
+Base.convert(::Type{Variable},x::Int64) = Constant(x)
 
 function caclulate_jacobian end
 

src/operations.jl

@@ -12,11 +12,8 @@ Base.:(==)(x::Operation,y::Number) = false
 Base.:(==)(x::Number,y::Operation) = false
 Base.:(==)(x::Operation,y::Void) = false
 Base.:(==)(x::Void,y::Operation) = false
-Base.:(==)(x::Variable,y::Operation) = y == Operation(identity,Expression[x])
-Base.:(==)(x::Operation,y::Variable) = x == Operation(identity,Expression[y])
-
-# Don't recurse inversion for Jacobians
-Base.inv(x::Operation) = x
+Base.:(==)(x::Variable,y::Operation) = false
+Base.:(==)(x::Operation,y::Variable) = false
 
 function Base.Expr(O::Operation)
     Expr(:call, Symbol(O.op), Expr.(O.args)...)

src/simplify.jl

@@ -1,45 +1,47 @@
-function simplify_constants(O::Operation)
+function simplify_constants(O::Operation,shorten_tree = true)
     O_last = nothing
     _O = O
     while _O != O_last
         O_last = _O
-        _O = _simplify_constants(_O)
+        _O = _simplify_constants(_O,shorten_tree)
         if typeof(_O) <: Operation
-            _O = Operation(_O.op,simplify_constants.(_O.args))
+            _O = Operation(_O.op,simplify_constants.(_O.args,shorten_tree))
         end
     end
     _O
 end
 
 const TREE_SHRINK_OPS = [:*,:+]
 
-function _simplify_constants(O)
+function _simplify_constants(O,shorten_tree = true)
     # Tree shrinking
-    for cur_op in TREE_SHRINK_OPS
-      if Symbol(O.op) == cur_op
-        # Shrink tree
-        if any(x->typeof(x)<:Operation && Symbol(x.op) == cur_op ,O.args)
-            idxs = find(x->typeof(x)<:Operation && Symbol(x.op) == cur_op,O.args)
-            keep_idxs = 1:length(O.args) .∉ (idxs,)
-            args = Vector{Expression}[O.args[i].args for i in idxs]
-            push!(args,O.args[keep_idxs])
-            return Operation(O.op,vcat(args...))
-        # Collapse constants
-        elseif length(find(x->typeof(x)<:Variable && x.subtype == :Constant ,O.args)) > 1
-            idxs = find(x->typeof(x)<:Variable && x.subtype == :Constant ,O.args)
-            other_idxs = 1:length(O.args) .∉ (idxs,)
-            if cur_op == :*
-              new_var = Constant(prod(x->x.value,O.args[idxs]))
-            elseif cur_op == :+
-              new_var = Constant(sum(x->x.value,O.args[idxs]))
-            end
-            new_args = O.args[other_idxs]
-            push!(new_args,new_var)
-            if length(new_args) > 1
-              return Operation(O.op,new_args)
-            else
-              return new_args[1]
-            end
+    if shorten_tree
+      for cur_op in TREE_SHRINK_OPS
+        if Symbol(O.op) == cur_op
+          # Shrink tree
+          if any(x->typeof(x)<:Operation && Symbol(x.op) == cur_op ,O.args)
+              idxs = find(x->typeof(x)<:Operation && Symbol(x.op) == cur_op,O.args)
+              keep_idxs = 1:length(O.args) .∉ (idxs,)
+              args = Vector{Expression}[O.args[i].args for i in idxs]
+              push!(args,O.args[keep_idxs])
+              return Operation(O.op,vcat(args...))
+          # Collapse constants
+          elseif length(find(x->typeof(x)<:Variable && x.subtype == :Constant ,O.args)) > 1
+              idxs = find(x->typeof(x)<:Variable && x.subtype == :Constant ,O.args)
+              other_idxs = 1:length(O.args) .∉ (idxs,)
+              if cur_op == :*
+                new_var = Constant(prod(x->x.value,O.args[idxs]))
+              elseif cur_op == :+
+                new_var = Constant(sum(x->x.value,O.args[idxs]))
+              end
+              new_args = O.args[other_idxs]
+              push!(new_args,new_var)
+              if length(new_args) > 1
+                return Operation(O.op,new_args)
+              else
+                return new_args[1]
+              end
+          end
         end
       end
     end
@@ -63,9 +65,8 @@ function _simplify_constants(O)
         else
             return O
         end
-    elseif (Symbol(O.op) == :+ || Symbol(O.op) == :-)  &&
-           any(x->typeof(x)<:Variable && (isequal(x,Constant(0)) ||
-           isequal(x,Constant(-0))),O.args)
+    elseif Symbol(O.op) == :+ && any(x->typeof(x)<:Variable &&
+           (isequal(x,Constant(0)) || isequal(x,Constant(-0))),O.args)
         # If there are Constant(0)s in a big `+` expression, get rid of them
         idxs = find(x->typeof(x)<:Variable && (isequal(x,Constant(0)) || isequal(x,Constant(-0))),O.args)
         _O = Operation(O.op,O.args[1:length(O.args) .∉ (idxs,)])
@@ -76,15 +77,18 @@ function _simplify_constants(O)
         else
             return O
         end
+    #=
     elseif O.op == identity
         return O.args[1]
+    =#
     elseif Symbol(O.op) == :- && length(O.args) == 1
         return Operation(*,Expression[-1,O.args[1]])
     else
         return O
     end
+    return O
 end
-simplify_constants(x::Variable) = x
-_simplify_constants(x::Variable) = x
+simplify_constants(x::Variable,y) = x
+_simplify_constants(x::Variable,y) = x
 
 export simplify_constants